1. Field of the Invention
The present invention relates to a composition providing a high and durable anti-fogging effect on the surfaces of glass, plastics and polymeric films.
2. Description of Prior Arts
In general, the surfaces of glass, plastics and polymeric films readily become foggy with the condensation of water vapor, and the transparency disappears or uneven reflection is caused on the surfaces. This phenomenon of fogging causes various troubles. For example, fogging on front, side or rear glass windows of an automobile or on spectacles results in great inconvenience and sometimes causes an accident endangering life. Further, when show-windows become foggy, no intended exhibiting effect can be attained, and when a polymeric film or glass of an agricultural green house or a dormer or other window of an oridinary house becomes foggy, transmission of light is inhibited and the growth of plants is checked or their health is injured.
Anti-fogging agents comprising anionic surface active agents, silicone type surface active agents or tricresyl phosphates have heretofore been used as agents for preventing fogging. However, none of the known anti-fogging agents have a sufficient durability of the anti-fogging effect. In order to attain the anti-fogging effect, it is necessary to increase the free energy on the surface and render the surface easily wettable with water. For attaining this purpose, a surface active agent is generally coated on the surface. However, the surface active agent is readily separated from the coated surface when wetted with water and the intended anti-fogging effect cannot be attained.